1. Field of the Invention
The present invention relates to an image processing apparatus, and particularly to an image processing system which prints, on paper or the like, image data stored in an image memory. The stored image data is such as an image obtained by developing a page describing language and image data obtained by scanning an original.
2. Description of the Related Art
A system is known comprising a color copying machine and a unit connected to the color copying machine so as to output a raster image by developing page describing language (referred to as "PDL" hereinafter) data and printing out the data on paper or the like. A system is also known for copying an image with a color copying machine by using a printing head having ink jet nozzles, which form a line, for repeatedly scanning the bands into which one page is divided and each of which has the same width as that of the printing head. Further, an apparatus is known for developing PDL data for each band width and outputting the data. This apparatus is provided in correspondence with a printer such that data of a page is divided into bands having the same width as that of the printing head and is printed out.
However, the above-described conventional systems have the following problems:
When a PDL developing device is connected to a color copying machine in which an image is divided into the above band units and copied so as to compose an image on the basis of an original image of the color copying machine and a PDL developed image, a memory unit or the like must be connected to the color copying machine so that the original image is read by a host computer through the memory unit, and an image is composed by the PDL image using image editing software of the host computer and is printed out through the memory unit or the PDL developing device. In this method, since there are large amounts of image data describing the original image, particularly a color image, much time is required for transferring the data from the color copying machine to the host computer through the memory unit. This method thus has the problem that since the large amount of data describing the original image must be processed by the host computer, the host computer is required to have a large-capacity memory, and the CPU is also required to have a high processing speed. In addition, a long time is required for transferring the PDL image and the original image to the color copying machine because the amount of data is significantly increased, as compared with transfer of PDL data alone. There is also the problem that much time is required for outputting the composite image.